1. Technical Field
The present disclosure relates to a charger and an electronic device.
2. Description of Related Art
Portable devices, such as smartphones and tablet computers, are usually powered by a rechargeable battery. When the rechargeable battery is run out, it is needed to charge the rechargeable battery via a charger, such as a power adapter. The common charger is connected to a mains socket to obtain an alternating current (AC) voltage, and then converts the AC voltage to direct current (DC) voltage and charges the rechargeable battery by using the DC voltage. The portable device has a charge control circuit to receive the DC voltage and charge the rechargeable battery. However, a voltage and a current output by the charger are constant, and the voltage output by the charger is greater than a charge voltage for the battery, which results in power consumption of the electronic device. For example, assume the voltage output by the battery is 5 volts (V), the current is 1 ampere (A), and the charge voltage is 3.7 V, then the electronic device would consume a power of (5−3.7) V*1 A=1.3 W, which causes power waste. Another consideration is that if the power consumed by the electronic device increases, the heat generation would increase too, to easily damage the electronic device. Besides, when the charging process for the battery is finished, people usually forget to pull out the charger from the mains socket. When this happens, the charger still outputs a voltage when connected to the mains socket, which prolongs the consumption of power.
A charger and an electronic device to overcome the described limitations are thus needed.